Blower.



1. E. GBEENAWALT,

BLOWER.

APPLICATION FILED MAY 12, I9l5 RENEWED AUG- 29- 1917 m N m m Patented Apr. 9, 1918.

3 SHEETS-SHEET l dblzzzE-Gmezzawa/fi L6L06o 1. E. BREENAWALT.

BLOWER.

APPLICATION man MAYlZ. 191s. RENEWED AUG- 29. m1.

. Patented Apr. 9,1918.

SHEETS-SHEET 2.

Q Y Q I INVENTOR. (/5121? E- Greenawah ATTORA'EY.

WITNESSES:

J. E. GREENAWALT. BLOWER.

APPLICATION FILED MAY 121-1915. RENEWED AUG. 29. 1911.

Patented Apr. 9, 1918.

, 3 SHEETS-SHEET 3.

ymsvxis WITNESSES: 1.7V 'VEJV TOR. I v 'JbhHE'QWHdMQ/Z Q [212 $2, Mi I f A TTORN'E' Y.

,neensoc.

TD snare: Parana un on.

Joan E. cnnnnawan'r, or nnnvnn, coLoo.

BLOWER.

Specification of Letters Patent.

Application filed. may 12, 1915, Serial Ito. 27,574. Renewed August .29, 1917. Serial No. 188,871.

To all whom z't may concern:

Be it known that 1, JOHN E. GREENAWALT, Y

bine compressors, blowers or pumps of the tion.

centrifugal type for compressing or moving fluids such as air and gases, the special object sought being the conversion of the velocity energy of such fluid into pressure by means operating to discharge the rapidly moving fluid from the impeller into the collecting or receiving scroll of the compressor without the formation of eddies or the production of shocks to the currents of the fluid in mo- As well understood in the art, the fluid as it leaves the impeller of a centrifugal machine, is under the influence of two source of energy, to wit, (a) the centrifugal force acquired by the fluid in its movement along the impeller blades, and (b) the kinetic energy contained in the fluid due to its velocity upon leaving the periphery of the impeller. The eificiency of such a machine is in a large measure .dependent on the extent of conversion of this kinetic or velocity energy into potentialenergy in the form of static pressure; and 1n the present embodiment of my invention special means are provided to efl'ect the necessary conversion of said velocity energy into a pressure head,

such means taking the form of ducts or.

channels which remove the fluid from the influence of the impeller, and conduct the same into the receiving or collecting scroll without shock or loss of energy caused by re-acting eddies in the fluid discharged from the impeller wheel, the ducts 0r channel being so disposed as to cause an even diflusion of the fluid by a lateral movement thereof after the fluid being finally leaving the impeller,

diflr'usion discharged from the'sides of the member on which the ducts are formed, into fore constructed, the diifusion vanes are disposed around the periphery of the impeller with their receiving ends supposedly tangent to the outlet velocity of the fluid, the vanes discharging the fluid nto the receiving scroll which is in turn connected with the eduction pipe. In practice however, only a small percentage of the fluid particles are projected from the impeller in a true tangential direction and the consequence is that the mass of the fluid strikes the vanes with considerable impact thus resulting in considerable reduction of'efliciency. In my improvement the diflusion vanes (or their equivalents) are disposed at a comparatively slight angle to the direction of flow of the fluid while under the influence of the impeller, said vanes forming spiral channels or conduits which receive the fluid immediately a it leaves the impeller, and guide and turn it in a gradual and definite manner laterally into the collecting scroll without material impact or Patented Apr. 9)., 191%.

shock, or the formation of re-actingeddies,

so that the full momentum and velocity f the rapidly moving fluid is availed of and utilized in the production of pressure in the Figure 1 1s a combined side elevation and middle vertical longitudinal section of a blower to which -my invention is applied; Fig. 2 is an end elevation of the blower; Fig. 3 is an enlarged vertical middle transverse section, parts being left in elevation; Fig. 4;

is a side view of the annular diffusion mem-' her or ring detached; Fig. 5 is a transverse section through the diffusion ring on the line 5.5 of Fig. 4; Fig. 6 is a sectional detail on the line 66 of Fig: 3, with parts broken away Fig. 7 is a face elevation of one of the 1 impeller blades with securing disk in section on the line 77 of Fig. 8; Fig. 8 is an elevational view at right angles to Fig. 7 the im peller shaft being in section; and Fig. 9 is a diagrammatic plan showing a modified form of diffusion ring.

Referring to the drawings, and for the present to l igs.v 1 to 8 inclusive, C repre- 65 paratus of centrifugal machines as heretosents a conventional blower casing having I the receiving scroll. In .the diffusion ap-- opposing, conical, machined side walls cw, 110.

w, spaced apart, between which rotates at a high speed an impeller composed of a series of radial blades B, the same being keyed or otherwise secured to the I impeller shaft S disposed transversely to said walls. The shaft S is mounted in bearings D, D, one end thereof being provided with a coupling member P which is secured to a corresponding member P of any motor or power shaft S for imparting rotation to the impeller. The casing is provided with induction or intake openings 0, O, and with the usual eduction leg E as well understood in the art.

In the present embodiment of my invention, the walls w, 'w, are provided with laterally and outwardly extending annular ofl'- sets or shoulders s, s, at points opposite, the tips of the impeller blades, said shoulders forming the inner walls of the collecting (or receiving scroll 1, the parts referred to being cast integrally in two sections which are su sequently assembled and fastened together through the flanges h, h. The inner faces of the offsets s, s, are disposed on a and the collecting scroll 1, the collecting chamber of the scroll being the space between the scroll walls and said ring 2, the latter serving (as presently will more fully appear) to properly diffuse the fluid as it leaves the impeller, and conduct the same into the scroll-chamber. Disposed on the inner face of the ring 2 on each side of a medial line m thereof, are a series of ribs or ivanes 3, said ribs being inclined at a slight.

angle to said medial line and extending therefrom to the side edges of the ring. Preferably, a rib or vane on one side converges to a common vertex with a rib or vane on the opposite side, thereby forming corresponding series of laterally diverging channels a between the ribs, the converging termini of the channels being disposed along the medial line as of the ring (Fig. 5). The width of the ring 2 is considerably in excess of the distance or gap between the side walls of the casing O at the tips of the impeller blades (Fig. 3), the ring when in position not only spanning said gap, but extending some distance over the ledges or shoulders s, 8, above referred to, it being understood that the ring is disposed symmetrically about the centralplane of rotation of the impeller blades. The inside diameter of the diffusion ring is such that when inserted into position (the sarhe being preferably made in two halves for ready asseminto the scroll chamber without any material bling), the free edges of the ribs 3 will, for. considerable portions of their" lengths rest on the inner faces of the shoulders 8, thereby closing the otherwise open peripheries of the channels a and converting the latter into tubular ducts, conduits or nozzles through which the air as it leaves the impeller is caused to travel before the same isdischarged into the scroll chamber (Figs. 3, 6).

These nozzlesor conduits being disposed on the surface of a cylinder and inclined to the axis thereof will naturally partake of the form of a spiral, to traverse which, the air currents entering the same from the impeller blades must travel a suitable distance circumferentially (of the ring 2 and the ledges s) and at the same time aterally, the air being finally discharged into the chamber of the collecting scroll 1 at-points between the sides of the ring 2 and the adjacent walls of the scroll. ,In a blowerhaving an impeller four feet in diameter, the circumferential travel of the air through the nozzles a would be in the neighborhood of thirty-five inches, the lateral travel or deflection thereof by reason of the slight inclination'ofl the nozzles, being only about four and one half inches before passing into the scroll chamber. With the diffusion ring 2 dis posed symmetrically about the central plane of rotation of the impeller, the inner ends, of the diverging channels a will terminate at said plane, and be in properposition to receive the fluid the instant it leaves the impeller blades. Thereafter the channels or nozzles will guide the fluid circumferentially, and gradually and definitely turn the same laterally and finally discharge the fluid shock or impact, and without the formation of re-acting eddies. By the employment of the difl'usion. channels or nozzles as here de-. scribed, the full momentum and velocity of the rapidly moving fluid as itleaves the impeller is utilized in the roduction of pressure in the chamber of t e collectin scroll, the diffusion of the fluid being broug t about. without material disturbance of the continuity of flow, velocity, or direction which the fluid as it leaves thedmpeller should possess to bring about a high efficiency in this type of apparatus.

The apparatus here shown is specially. adapted for use with air or gases, that is to say, with elastic fluids, and obviously may be operated as a compressor or as an exhauster for producing a partial vacuum; and while'the apparatus illustrated is eminently adapted for the purpose here in View,

I may depart therefrom in. many particulars Without a departure from the nature or spirit of my invention. As an instance of such departure, the dilfusing ribs or vanes need not 'meet at a common vertex as shown in the first form described but may be stag- 2 and the ribs or vanes by 3, forming chanvit!) gered as shown diagrammatically in Fig.

9 where the diffusion ring is indicated by nels a divergin from the medial line w. Features shown liiut not alluded toare well understood in the art and need no description in the present connection.

Obviously, the invention is not restricted in its application to elastic fluids such as air or gases, but may be employed in connection with inelastic fluids such as water and the like, as for example in centrifugal pumps for pumping water, oil, or other liquids. It may be stated in passing, that in the operation of the'blower the impeller is given a rotation in'the direction indicated by the curved arrow in Fig. 1, and by the straight arrow in Fig. 5, that is to say the impeller should rotate in a direction toward the vertices of the converging channels or nozzles a (or toward the vertices of the converging ribs 3), to properly direct the currents as they leave the impeller blades, into and through the channels of the difi'usion member 2.

In the present example, the impeller blades B are secured to angles d fastened to a disk m which is keyed to the shaft S, the edges of the blades being stifi'ened by angles t; but any other manner of constructing the impeller and fastening the blades to the impeller shaft may be resorted to, this feature not being important in the present connection.

Having described my invention what I claim is: i

1. In an apparatus of the character described, a rotary impeller, a collecting scroll for the fluid, and a member interposed between the scroll and impeller for conducting the fluid from the impeller to the sides of the scroll chamber.

2 In an apparatus of the character descrlbed, a rotary impeller, a casing therefor provided with induction and 'eduction means, a collecting scroll encompassing the periphery of the impeller, and a member interposed between the impeller periphery and the scroll for conducting the fluid from the impeller to the sides of the scroll chamber.

3 In an apparatus of the character described, a rotary impeller, a collecting scroll disposed adJacent the impeller, a peripherally closed ring-like member interposed between the periphery of the impeller and the scroll, and suitable conduits disposed on said member for conducting the fluid from the impeller to the scroll chamber.

4 In an apparatus of the character described, a suitable impeller, a collecting scroll, and a laterally diflusing member interposed between the impeller and scroll for discharging the currents into the scroll chamber.

retreat 5. In an apparatus of the character described, a suitable rotary impeller, a 001- j rents leaving the impeller, into the scroll chamber and thereby converting the velocity energyof said currents into a static pressure head within said chamber.

6. In an apparatus of the character described, a rotary impeller, abollecting scroll, and means interposed between the periphery of the impeller and the scroll for circumferentially and laterally diflusing the fluid as it leaves the impeller, and discharging the same into the scroll chamber.

7. In an apparatus of the character described, a rotary impeller, a collecting scroll,

and an annular member or ring interposed between the periphery of the impeller and scroll and provided with spiral passageways or conduits for circumferentially and laterally diflusing the fluid as it leaves the impeller and discharging the same into the scroll chamber.

'8. In an apparatus ofthe character de-v scribed, a rotary impeller, a collecting scroll, a ring interposed between the scroll and the periphery of the impeller, suitable conduits on the inner face ofthe ring disposed t an angle to the plane of rotationof the impeller and terminating respectively at points contiguous to the central rotation plane of the impeller and at the sides of the ring within the scroll chamber, and operating to difiuse the fluid circumferentialldy and later'ally as it leaves the impeller an the same into the scroll chamber.

discharge 9. In an apparatus of the character described, a rotary impeller, a collecting scroll, a ringl interposed between the scroll and the perip cry of the impeller, suitable conduits on the ring disposed oneach side of a medial line thereof and inclined at a slight angle to said line, the outer ends of the conduits opening into the scroll chamber, whereby the fluid as it leaves the impeller is diflused c rcumferentially and laterally on opposite sides of said medial line of the ring, and the fluid discharged into the scroll chamber.

' l0..In an apparatus of the character described, a rotary impeller, a collecting scroll, a ring interposed between the'scroll and the periphery of the impeller, su1table rib or vane formations on the inner faceof the ring disposed oneach side not . teropening at their outer ends into the scribed, an annular difiusion member vided with channel formatlons dlspose s roll chamber, the inner ends of the channels being disposed in proximity to the center of the'periphery of the impeller, whereby the fluid leaving the impeller is difi'used circumferentially. and laterally and delivered on opposite side into the scroll chamber.

- 11. In a entrifugal blower, a suitable casing an outer collecting scroll, a rotary impel er mounted in the casing within the scroll, and means forlaterally diverting the fluid as it leaves the impeller, in circumfer-' ential paths disposed on opposite sides of the central plane of rotation of the impeller, and discharging the same into the scroll chamber.

12.- In an apparatus of the'character deroon each side of a medial ircumferential line, said channels being disposed ata slight incline to aid lineand having discharge ends terminating at the sides of said annular member. I

13. In an apparatus of the character described, a diffusion ring provided on its inner surface with series of ribs divergin laterally from common vertices dispose along a medial circumferential line and at I a slight ngle to said line, the ribs forming qorrespondmgdiverging channels having racism their terminals respectively at said has and at the sides of the ring.

14:. In an apparatus of the character described, a rotary impeller, a collecting scroll,

and an annular laterally discharging member interposed between the impeller and the the kinetic energy of the find leaving the impeller into Walls of-the scroll for convertin potential energy in the form of static pressure.

15. In an apparatus of the character de-' scribed, a rotary impeller, a collecting scroll,

and an annular circumferentially guiding and laterally diflusing member interposed between the impeller and the walls of the scroll for converting the kinetic energy of the fluid leaving the impeller into potential energy in the form of tatic pressure.

16. In an apparatus of the character described, a' suitable. impeller, a collecting scroll, and a laterally difiusing member for receiving the fluid as it leaves the impeller and discharging the ame] into the scroll chamber.

In testimony whereof I- aifix my signature, in presence of two witnesses. 1 JOHN E. GREENAWALT.

Witnesses: I

HAROLD GREY, FRANCES 'WEINBERGER. 

